Device for launching a thread by jet action of a fluid to be used in conjunction with a loom



June 24, 1969 P. VAN'MULLEKOM 3,451,437

DEVICE'FOR LAUN NG A THREAD BY JET ACTION OF A FLUID v TO BE USED IN CONJUNCTION WITH A LOOM Filed July 12, 1967 Sheet of 2 June 24, '1969 H. P. VAN" MULLEKOM 3,451,437 DEVICE FOR LAUNCHING A THREAD BY JET ACTION OF A FLUID TO BE USED IN CONJUNCTION WITH A LOOM 1 Filed July 12. 1967 Sheet 3 of 2 United States Patent 3,451,437 DEVICE FOR LAUNCHING A THREAD BY JET AC- TION OF A FLUID TO BE USED IN CONJUNC- TION WITH A LOOM Hubert Peter van Mullekom, Voortseweg 11,

Deurne, Netherlands Filed July 12, 1967, Ser. No. 652,978 Claims priority, application Great Britain, July 14, 1966, 31,764/ 66 Int. Cl. D03d 47/30 US. Cl. 139-127 5 Claims ABSTRACT OF THE DISCLOSURE Background of the invention The invention relates to a device for launching a thread by jet action of a fluid under pressure, which device is provided with a jet nozzle and a movable member, which member, being movable between two end positions with respect to the jet nozzle, is adapted for presenting a thread to this jet nozzle. Further the movable member in one end position cooperates with the jet nozzle in such a manner that the thread will enter the jet nozzle.

Such a device is adapted to be used in conjunction with a loom in which a weft is to be inserted into the shed by jet action of a fluid under pressure. Mostly air under pressure is used and the thread is blown into the shed. A liquid, such as water, can, however, be used alternatively for weft insertion.

When the production speed of a loom, in which the weft is to be inserted into the shed by jet action, is increased, difliculties arise, because the fluid has less grip on the thread at the moment when the thread is still stationary, i.e. at the beginning of the weft insertion, than it has subsequently after the thread is in motion.

Increasing the fluid pressure in order to obtain a high initial speed of the fluid in the jet nozzle is not desirable.

It has already been proposed to form a loop at the leading end of the thread and to position this loop in front of a nozzle, in order to improve the grip of the fluid on the thread. However, in this case also the speed of the fluid can still not be increased, because it is possible that the structure of the thread may be impaired by the strong jet action and the thread may be blown apart. When the fluid is 'a liquid instead of a gas or air the structure of the thread is less liable to be damaged, but the use of a liquid has the drawback that no large quantities of liquid can be used for the launching of a thread.

It has already been proposed, in looms having weft insertion by jet action, to give the weft an initial speed by mechanical means after which the blowing nozzle becomes operative for a further conveying of the weft by jet action. Good results have been obtained with an arrangement which operates in this manner, but it is possible to increase the effect of the jet action and the object of the invention is to improve the effect of a jet-operated device for launching a thread.

Patented June 24, 1969 ice Summjary 0f the invention According to the present invention, a device for launching a thread is characterized in that the movable member previously referred to is provided with a discharge opening for a fluid, which discharge opening is positioned in such a manner that a jet of the fluid leaving it is directed towards the path of the jet of the jet nozzle and impinges on the thread inserted into the jet nozzle. The movable member preferably forms a component of the jet nozzle when the thread is launched.

In a practical embodiment of the invention, the movable member has the form of a hollow needle, the point of which is centrally positioned within the jet nozzle in one end position of said member and is provided with a seat for the thread which extends in front of the needle point.

The fluid which can flow through the hollow needle may be used as the primary fluid of the jet nozzle. In this case, the movable needle forms the main component of the jet nozzle. With such an arrangement the point of the needle may be provided with a collar-like head which tits in a central part of the hopper-shaped jet nozzle, leaving an annular slot between this head and the inner circumferential wall of the hopper-shaped part of the blowing nozzle.

A secondary fluid, e.g. the surrounding air, can be conveyed through this annular slot together With the thread. Moreover, if desired, a primary, secondary and tertiary fluid can be used in the jet nozzle. With such a device, the point of the needle may be arranged to fit in a central passage of an annular nozzle. The fluid which flows through the needle can be considered as a primary fluid and the fluid which streams out of the annular slot can be considered as a secondary fluid. The tertiary fluid can be the surrounding air which enters the blowing nozzle through the central passage surrounding the needle. In all the arrangements referred to above, the needle cooperates with a jet device and an initial velocity can be imparted to the thread'in a mechanical manner during the movement of the needle, while a jet action is also exerted on the thread.

A further advantage of the invention is that it makes possible the use of a fluid having a higher density than that of the gas or air used to form the jet, e.g. a liquid. According to the invention this may be achieved by connecting the interior of the hollow needle to one or more supplies of fluids having a diflerent density. This enables a small quantity of a liquid, e.g. a drop of water, to be sprayed against the thread extending in front of the point of the needle. When now the thread is to be launched by air under pressure, the drop of water, which comes into contact with the thread, prevents the thread from being blown apart by the air under pressure. The possibility of destruction of the thread is now decreased.

The use of these features enables the thread to be launched with a high velocity, because the thread already has an initial speed obtained by the displacement of the movable member as well as by the effect of the jet of air streaming around the point of the movable member, while at the same time enabling the thread to be strengthened by a drop of liquid.

Brief description of the drawings FIG. 1 is a perspective view, partly broken away, showing a loom provided with a device for launching a weft into the shed of the loom;

FIG. 2 is a fragmentary longitudinal section of a device for launching a thread by jet action of a fluid under pressure, illustrating an axially movable hollow needle in its fully advanced position and the operation of means for discharging primary and secondary air into a nozzle;

FIG. 3 is a fragmentary longitudinal section of a simplified embodiment of a device according to FIG. 2 showing the hollow needle withdrawn from the nozzle;

FIG. 4 is a view corresponding to that of FIG. 3 showing the needle in the fully advanced position and also showing means for introducing a small quantity of liquid into the hollow needle; and

FIG. 5 is a longitudinal section of a device similar to that shown in FIG. 2, showing how the blowing nozzle can co-operate with a shaft for temporarily storing a measured length of a thread.

Description the preferred embodiments Although the device according to the invention can be used in conjunction with any apparatus in which a thread has to be launched, its most advantageous use is in conjunction with looms in which a weft is adapted to be inserted into the shed by jet action of a fluid, because a weft must be accelerated from its stationary condition to a very high speed.

FIG. 1 shows a loom of this character in which a thread 1 is drawn from a stationary thread package 2 by means of continuously rotating conical rollers 3 and 4. The speed of rotation of those rollers 3 and 4 depends on the production speed of the loom and the thread can be located at a definite position on the circumference of the conical roller 3 by means of an adjustable thread guide 5 in order to match the speed of the thread with that required for supplying to a device for making up a weft.

The device for making up a weft is known and in general such a device comprises a shaft or storage space 6 for taking up a periodical surplus of the thread 1. Further a shaft or channel 7 is provided in which a thread is temporarily stored in the shape of a loop. Thread clamps and thread guides co-operate with the shafts 6 and 7 in order to obtain a measured length of the thread 1 which is to be stored in the shaft 7. The thread clamps and thread guides are not indicated, because they are not a part of the invention. The shaft 7 co-operates with a jet nozzle 8 for projecting the measured length of the thread out of the shaft 7 into the shed. In a double action loom, a jet nozzle and a device for making up a weft are situated also at the other side of the shed. The additional jet nozzle provided in this case is indicated by the reference numeral 8a.

Preferably, air under pressure is used as a fluid for creating the jet action and for conveying the thread into the shafts and the supply of air to the appropriate parts of the device for making up a weft is controlled by means of valves 9, which in turn are controlled by means of a cam shaft 10. The cam shaft 10 is driven by the main shaft of the loom. A guide 11 mounted on the shaft 7 is located in parallel alignment with the axis of the jet nozzle 8. The guide 11 is adapted to receive a movable member and the purpose and operation if this movable member will be described later with reference to FIGS. 2 to 5.

Referring now to the jet nozzle, generally indicated by the reference numeral 8, as shown in FIG. 2 an annular slot 13 is provided within a mixing tube 12. This annular slot actually forms the jet nozzle for a fluid such as air, which streams out of an annular chamber 14. The allnular chamber 14 situated around a hopper-shaped wall 15 defining a central passage 16 for secondary air and for a thread 1. The annular chamber 14 is connected to a source 18 of fluid under pressure by means of a line 17. A control valve 19 situated in the line 17 is arranged to be operated by a member (not shown) which runs synchronously with a main shaft of a machine such as a loom. By opening the control valve, the fluid is admitted to the nozzle at the desired moment so that it issues in the form of a jet from the annular slot 13. The fluid which streams out of the annular slot 13 will be mixed with air which enters the mixing tube through the central 4 passage 16 and a strong jet of the mixture will leave the mixing tube 12.

When a thread 1 is supplied through the central passage 16, this thread will be sucked into the jet issuing from the annular slot 13 by means of the secondary air entering the passage 16 and the thread will be launched by the action of the jet streaming out of the mixing tube.

The presentation of the thread 1 to the jet streaming out of the annular slot 13 is performed in a special manner. A thread 1 extending behind the central passage 16 and having its leading end 1a clamped in a thread clamp 1b (shown in FIG. 3) located behind this passage 16 can be engaged by the front end of a movable member 20, as the member 20 moves toward the jet nozzle 8. FIG. 3 shows the thread 1 being engaged in a similar manner by the front end of a movable member 20a.

To ensure a good hold on the thread, the movable member 20 is provided with a V-shaped notch 21.

The movable member 20, which has the form of a hollow needle, is reciprocated between two end positions by driving means (not shown) which are synchronised with a moving part of the machine on which the device is mounted. The movable member 20 may, for example, be driven by means of the cam shaft 10 in a loom according to FIG. 1. The thread which extends in front of the hollow needle constituting the movable member 20 enters the notch 21 when the hollow needle moves towards the outlet end of the nozzle 8. Further a thread clamp 1b (shown in FIG. 3) is released so that the leading end 1a of the thread becomes free. The first part of the thread in the notch 21, is bent around the needle 20 and such an arrangement of the thread is advantageous, because the jet issuing from the annular slot 13 has a good grip on this end of the thread. As the needle 20 is hollow, a fluid can also flow through the interior of the needle 20. For this purpose, the Wall of the hollow needle may be provided with a lateral opening 22, which co-operates with an inlet opening 23 in the guide 24 for the needle. The inlet opening 23 is connected to a source 18 of fluid under pressure by means of the line 25. It is obvious that, as soon as the opening 22 in the wall of the hollow needle 20 coincides with the inlet opening 23, the fluid will stream out of the point of the hollow needle. The jet created in this manner will engage that part of the thread which extends across the notch 21 of the needle thus launching the thread. As the thread has already an initial speed as a result of the movement of the needle 20, the possibility of blowing apart the leading end of the thread by the jet streaming out of the needle 20 is decreased. As a result of the initial speed imparted to the thread by the movement of the needle, the jet passing through the needle need not 'be so strong for launching the thread as in the case where the thread has no initial speed at all.

The commencement of launching of the thread can be considered in three steps, i.e. a first initial speed imparted to the thread by the forward movement of the needle 20, a second initial speed which is imparted by the jet leaving the hollow needle and a third initial speed or acceleration which is obtained as soon as the thread comes into contact with the strong jet issuing from the annular slot 13-. These three steps of initial speed are so close together that they can be considered as only one step.

The jet nozzle can be of very simple construction as shown in the FIGURES 3 and 4. In the embodiment illustrated in these two figures, the jet nozzle is formed by a hopper-shaped solid of revolution 15a and the hollow needle 20a possesses near its point a collar-shaped head 26. The point of the needle 20a is formed with a V-shaped notch 21 in which the thread 1 can fit. The collar-shaped head 26 tapers inwardly towards the point of the needle 20a. The head 26 is tapered in such a manner that an annular slot is left between the inner surface of the hopper-shaped solid of revolution 15a and this tapered part of the head 26 when the hollow needle 20a is in one of its extreme end positions in the jet nozzle 8, as indicated in FIG. 4. The thread together with secondary air can be supplied through this annular slot. The fluid for creating a primary jet streams through the hollow needle a.

To facilitate the use of fluids of different densities, the hollow needle is provided with an additional inlet 27, as indicated in FIG. 4. A drop of water can be injected into the hollow needle through this inlet 27, which drop of water will be discharged from the hollow needle together with air. The drop of water will moisten the part of the thread 1 which rests in the notch 21, and such moistening will cause the fibers in the thread to adhere together more strongly, so that the structure of the thread will be less likely to be disrupted by the fluid which streams out of the hollow needle.

In the embodiment according to FIG. 5 the jet nozzle 8 of FIG. 2 is provided with a shaft 7 in which a measured length of a thread is temporarily stored in the form of a loop. The shaft 7 is positioned behind the hopper-shaped member 15. The manner in which the thread is positioned in the flat channel-shaped internal space 28 of the shaft 7 will not be described, because the supplying of a thread to a shaft is generally known. Preferably, the loop enters the channel-shaped space 28 by jet action of a fluid, which fluid streams out of the nozzle 29. The manner in which the hollow needle 20 is guided is clear from FIG. 5. The part 30 of the needle 20, which is bent upwardly, fits in a holder, which is slidably supported in the guide 11 (FIG. 1). In one end position, the lateral opening 22 of the hollow needle coincides with an inlet opening 23 from the valve 31. A similar valve '31 is connected to the annular chamber .14 of the jet nozzle 8. When now fluid such as air is supplied to the valve 31 through the line 17a, each valve disc 32 will be pressed on a seat 34 and air can flow around the circumference of the valve disc 32 to the chamber 33. The capacity of thischamber 33 can be adjusted. When now the pressure in the line 17a is relieved e.g. by means of a pressure-relief valve (not shown), the air stored in the chamber 33 will still be under pressure and therefore will begin to flow back toward the line 17a, thus flowing upward around the circumference of the valve disc 32. The kinetic energy of the air flowing upward against the valve disc 32 will then lift the valve disc 32 from its seat 34 and will press the valve disc 32 against a seat 35, thus cutting 011? the flow of air from the chamber 33 into the line 17a. At this moment the air will flow from the chamber 33 between the valve disc 32 and its seat 34 to the inlet opening 23, in one case, and to the annular chamber 14, in the other case. Owing to this a measured quantity of air will be forced through the hollow needle 20 and through the annular slot 13. The fluid pressure in the line 17a will be relieved at the moment when the point of the hollow needle 20 pushes the thread 1 into the interior of the jet nozzle 8.

A very quick but easy launching of the thread by the jet nozzle 8 is performed in this manner.

What I claim is:

1. In a device for launching a thread by jet action of a fluid under pressure, in combination, a nozzle for discharging a jet of fluid, and a member "which is movable relative to the nozzle between two end positions, for presenting a thread to the nozzle, wherein the improvement comprises a discharge opening for a fluid, which is so located in the movable member as to discharge a jet of fluid in such a direction as to merge 'with the jet of fluid from the nozzle and to impinge upon the thread presented to the nozzle.

2. In a device according to claim 1, wherein said movable member is in the form of a hollow needle, the point of which is positioned centrally within the nozzle in one end position of the movable member, and is provided with a seat for the thread which extends across in front of the point of the needle.

3. In a device according to claim 2, wherein said nozzle is hopper-shaped, and a collar-like head which is provided on the point of the needle and which fits centrally in the hopper-shaped nozzle so as to leave a clearance, between the head and the interior of the nozzle, forming an annular slot to admit secondary air.

'4. In a device according to claim 2, said nozzle having an annular slot for discharging fluid, and having a central passage in which the point of the needle is positioned in one end position of the movable member.

5. In a device according to claim 2,-a fluid connection for supplying to the interior of the hollow needle a fluid whose density is different from the density of the fluid discharged by the nozzle.

References Cited UNITED STATES PATENTS 3,367,371 2/1968 Van Mallekorn.

HENRY S. IAUDON, Primary Examiner. 

